By Debmedia Technologies LLP · Kolkata, India · Updated
What Is an SPF Record?
SPF, short for Sender Policy Framework, is a DNS record that lists the servers allowed to send email for your domain. It is published as a TXT record that starts with v=spf1. Receiving mail servers read it to decide whether a message really came from you.
Without a correct SPF record, legitimate mail is more likely to land in spam, and criminals find it easier to forge your address. This checker finds the record, follows every include and reports problems in plain language.
How to Use This SPF Checker
- Enter your domain, for example example.com.
- Select a resolver and press Check SPF.
- Read the record shown at the top, then the checks below it.
- Use the mechanism table to see each include, address and lookup, level by level.
SPF Syntax at a Glance
| Part | Meaning |
|---|---|
| ip4: / ip6: | Allows a specific IP address or range. No DNS lookup is needed. |
| include: | Also allows everything in another domain’s SPF record, such as your email provider. |
| a / mx | Allows the addresses of your own web server or mail servers. |
| -all | Hard fail. Mail from anywhere else should be rejected. |
| ~all | Soft fail. Mail from anywhere else is suspicious but accepted. |
| +all | Allows everyone. This disables protection and should never be used. |
The 10 DNS Lookup Limit
SPF allows no more than 10 lookups in total. Each include, a, mx, exists and redirect counts as one, including those inside included records. Passing the limit produces a permanent error, and receivers may treat your mail as unauthenticated. The checker counts them for you and warns when you get close.
To reduce lookups, remove providers you no longer use, replace a and mx with fixed ip4 ranges where the addresses are stable, or ask your provider for a flattened record.
Common SPF Mistakes
- Two SPF records. Only one is allowed. Merge them into one line.
- A missing “all” at the end. Without it, unlisted senders are not handled.
- Using ptr. It is slow and deprecated by the standard.
- Forgetting a sender. Newsletter tools, invoicing software and help desks all send mail as your domain and must be included.
- Typos. A single wrong character can invalidate the whole record.
The full rules are in RFC 7208, the SPF specification.
SPF Works Best With DKIM and DMARC
SPF checks the server that sent the message. It does not protect the visible From address on its own. For stronger protection, add a signature with the DKIM key tester and a policy with the DMARC policy checker. Make sure inbound mail is set up properly too, using the mail server lookup.
Why Run an SPF Record Checker Regularly?
An SPF record is not something you set once and forget. Every new email tool, newsletter service or help desk adds another sender, and every old service you drop leaves unused entries behind. Running an SPF record checker after each change keeps the record valid and under the lookup limit.
It is also a quick way to confirm that a record copied from a provider guide was pasted correctly. Many deliverability problems trace back to a record nobody has looked at in months, so bookmark this SPF record checker and run it every few months for any domain that sends email.
Frequently Asked Questions
Disclaimer: results come from live requests and can change as records and servers change. We cannot guarantee that every answer matches what every visitor sees.